Tobacco stemming



July 11 1939 w. B. BRQNANDER TOBACCO S TEMMING ATTORNEY Patented July 11, 1939 UNITED STATES PATENT OFFECE TOBACCO STEMMING Application November 5, 1935, Serial No. 48,353

Claims.

This invention relates to tobacco stemming and has for its general object cutting the blade portions of tobacco leaves from the stem in an improved manner.

5 The invention is particularly designe-d for, al-

though not limited to the stemming of cigar filler and wrapper tobacco wherein the tobacco is relatively valuable and wherein also it is desirable to retain the strips in flat uncrumpled condition.

In stemming or stripping machines for this purpose, it has hitherto been the common practice to feed the stem of the leaf between two flanges and a double-edged knife placed between and cooperating with the flanges so that the tobacco leaf is sheared from the stem. While machines of this type have been widely used with satisfactory results, they leave a portion of the leaf blade along the stem, particularly toward the small end of the stern, since the knives are a fixed distance apart and do not follow the taper of the stem. Also in such mechanisms it is important that the leaf be carefully guided in order to prevent the knives from cutting across the stems, which is also likely to occur when the stems are crooked. These machines do not lend themselves to automatic feeding of tobacco leaves because of the necessity of careful guiding referred to above.

The principal objects, therefore, of. the present invention are to provide an improved stemming unit which avoids some of the above difficulties and limitations, and has peculiar advantages of its own such for instance as close stripping and a tendency to be selfguiding on the tobacco stem.

With these objects the invention contemplates the provision of flexible endless cutting or sawing members designed to hug and follow a stem surface. To secure this result, it is one of the objects of the invention to provide for yieldingly urging the stemming elements into contact with the stem. In so doing, the danger arises that the cutting surfaces pressed close to the stemnnay cut into or cross the stern and it is, therefore, 45 an important object of the invention to minlmize this possibility by rounding or bevelng the face or edge portion of the stemming' element adjacent the stem. surface. This also has an advantage in that it ten-ds to guide the stem be- 50 tween the cutting or sawing elements despite crookedness of the stem and the lack of hand guiding. Indeed, it is contemplated that With the present invention the stem, once the butt end is passed between the stripping elements,

55 may be pulled. through the same without. need of manual guiding of the trailing -portion of the leaf and stem. Thus, the present stemming unit lends itself to mechanical feeding and makes possible a decrease in the attention required by the operator. 6

the cutting element is not inten-ded to be rigid, l0*

it may be made quite narrow, `both transversely of the axis of the stern and also lengthwise of the stem axis, particularly as to the portion engaging the stem. This` makes it possible for crooked stems tov weave their way through the l5 space between the cutting elements for close stemming, regardless of the contours of the stem and makes possible clean stemming of a type of stern which offers a great deal of diiculty with existing stripping machines. 20

Another object of the invention is to avoid in this type of stripper a shearing action and thus eliminate ledger plates and similar structure requiring a xed distance between the cuts on each side ofthe stem and detracting from its flexi 25 bility in fitting varying widths of stems.

Another object is to provide a novel method of stemming wherein the blade portions of the tobacco leaf are sawed apart from the stem. along the surface of the stem. 30u,

With the object of showing a selected. embodiment of the invention, the invention is shown in combination with a booking drum, but it should` be understood that the stripping unit referred to is useable in a wide variety of machines and applications.

With these and other objects not specifically mentioned in View of the invention consists in certain steps and constructions which will be hereinafter fully described and then specifically pointed out in the claims hereunto appended.

In the accompanying drawing, which forms` a part of this specification and in which like characters of reference indicate the same or like parts, "'l

Fig. l is a front elevation, partly broken away, showing the improved stemming unit applied to a tobacco booking machine;

Fig. 2 is a side elevation of the machine illustrated in Fig. 1 on line 2-2 thereof; and 50" constructions selected to illustrate the invention are but certain of many possible embodiments of the same. The invention, therefore, is not to be restricted to the details illustrated and described, nor to the particular embodiments chosen as illustrative of the invention.

Referring to Figs. 1 and 2 of the drawing, the stemming unit referred to is shown for purposes of illustration in combination with. a booking mechanism, the side frames III of which are held together by tie rods II and carry the ldrum shaft I2, drive shaft I3, roller shafts I4, I5, and I6;

screw studs I1, and fulcrum shafts IB and- I9. On shaft I6, which has a flanged roller 29 and is swingable by a handle 2|, are xed arms 22 carrying between them a shaft 23 on which the rollers 24 for the up-perloopends are mounted, and a rod 25 against which the-loop belts rest in their open position when the handle 2l has been swung in the direction of the arrow-shown in Fig. 2. On the studs I1 are swingable endbrackets 26 which are joined by the lead-in guide plate 21 and carry a shaft 28v which has rollers 29 for the lower loop-ends. The brackets 26 are swingable by means of crank arms 30 connected by links 3| to arms 32v on shaft I8, one of the latter arms having a handle 33. for this purpose. By turning the handles 2 I and 33 in the directions of the arrows, the ends of the loops 34 are raised f off the drums 35, thereby permitting periodic re-l Y moval of the leaf books B from themachine. Y

The booking belts 34 which surroundthe major' portion of the circumference of the drums 35 are looped around rollers 24 on shaft 23, runY over rollers 2U on shaft I6, over roller 36 on shaft I4', over flanged rollers 31 carried by arms 38 loose on shaft I 9, and over rollers 39 on shaft I5, and are nally'looped around rollers 29V on shaft 28. From thefhubs of arms 38 extend arms 40 on which are hung weights 4I which keep the belts 34 at a constant tension as the thickness Yof the leaf-books B on drum 35 increases during the operation of the machine. l

VTne'dmin 35 of the booking mechanism is` driven from shaft 28 by belts 34, the shaft 28 having a sprocket 42 driven by a chain 43 from a sprocket 44 on shaft YI3 on which is mounted a pulley 45 driven by'a belt 46. The chain 43 runs over idlers 41 and 48, the latter Vof V,which isV carried by an arm 49 pivoted toY frame I8 and held in tension by a spring50to enable the chain to follow the movement of shaft 28 when the same is swung into the open position by turning handle 33. The two halves of the booking drum- 35are separated by flanges 5I between which the stems S of the leaves on the lead-in plate 21 are inserted by the operator.

For the purpose of supporting the endless band saws'51, vthere is provided across the sideV frames I0, a bracket 52 which carries pairs `of shafts 53 and 54 on which are mounted pulleys 55 and 56, respectively. These pulleys vcarrying thetwo endless band-'saws'51 are drivenV in the Y direction of the' arrows by chains 58 running over sprockets 59 on shafts 6U driven by bevel gears 6I from the drum shaft I2 ofthe machine.

The band-saws 51 run over guide pulleys'BZ and 63, the` former of which is stationary while the'latter is mounted on a swingable arm 64 pivoted on bracket 52 and held by a spring 65. The tension of spring holds the saws'51-in Acontact at the guide pulleys so that the saws are yieldingly pressed against the stem S' passing between them on plate 21 and thus closely follow:

. the axis of ther stem. K, z

2.In a tobaccostemming machine, the lcom'-, Y

` 69 with the pulley-carrying end of arm 64, thereby overcoming the tension of spring 65 and causing the saws 51 to separate,'although such an arrangement may be dispensed with as by pushing the stem down from above at the front where lthe belts converge in V formation. The entering stem rests on a roller V1li turnable on a shaft v 1 I supported in bearings 12 on plate 21, thisY Y roller supporting the stem against the Vdownward pressure of the moving banding saws.

The teeth of the band saws are set pointing or aring awayv from each other and the stems on their inner sides. For this purpose they may be fchamfered toa beveled or curved shape 'as shown at l51 in Fig; 3, thereby permitting the stem to enter smoothly between the saws bearing against it, and preventing the latter from cutting into the sides of the on-coming stemwhich'may, owing to the pressurer of spring 65, bulge beyond the contacting sides ofthe saws.

The inclination ofthe inner faces of the sawi ing instrument relative to .the stem .in a direction flaring away from the stem surface toward the cutting edge isy of importance because it enables the blades to hug the stem closely and thus obtain clean'stemming from butt to tip while minimizing danger of cutting across `the stem. This -same feature makes possible pulling the stem through thestripping elements, with crooked stems .guiding themselves through said elements by contact with the inner surfaces of the element.

In connection with the operation of the illustratedstemming mechanism, it is noted that the outspread y blade portions or laminae of `the leaves after` being cutrfrom the stem by the band saws pass between the book B on the drum them to out the laminae from the stem,- driving means for imparting cutting movement to said edges, a pressure element engaging at least .one of-saidmembers', and'means yieldingly urging said pressure element against said member toward the 'f' other member .to cause.. said members to snuglyY engage the sides of stems of varying diameter;

said endless members being arranged to co-V operate against opposite sides of a taperingstem progressively' from lbutt. to tip yfor severingfthe" laminae along their juncture with the stem, without-waste, actinggfor that purpose. as sensing means,` regardless normallyof;V the 'bodily dis- V placement ofthepressure element relatively to binationwith a pair @of .iiexible endless cutting members havingadjacentcutting edges arranged to receive the stem of al tobacco leafbetween them, means to support said cutting members` in position to-be brought together into contacting relation-at a stripping stationto cutthe laminae i from the stem,` mechanism for yieldingly pressing.

said members against the sidesnof a leaf stemt.-

inserted-,th'erebetween- 'butt .first to cause lsaidj members to snugly engage stems of varying diameter along the entire length of the stems, and driving means for imparting cutting movement to said edges.

3. In a tobacco stemming machine, the combination with a pair of flexible endless saws havlng adjacent cutting edges arranged to receive the stem of a tobacco leaf between them to cut the laminae from the stern, the faces of said saws, nearest the stern, adjoining the cutting edge of the saw, being inclined backwardly and outwardly with respect to the direction of movement of the stem, to provide a tapered entrance for the stem and to avoid cutting into the same, a roller on which the entering stem is supported against the downward pressure of the saws as it passes therebetween, while free lateral flexure of the saws transversely to their broad faces is permitted, driving means for imparting cutting movement to said edges, and means behind said members for drawing the leaves butt rst through said members, whereby the trailing portion of the leaves will be left free in order that the same may be drawn through said members without guiding.

4. In a tobacco stemming machine, the combination with a, pair of flexible endless saws disposed with their broad faces side by side and having adjacent cutting edges arranged to receive the stem of a tobacco leaf between them; means to support said saws in position to be brought into a position in which said faces approach each other with an interval Yless than that of the thinnest stern part to be stripped, mechanism for pressing said members against the sides of a leaf stem inserted therebetween butt rst to cause said saws to snugly engage stems of varying dameter progressively along the entire length of the stems, with a pressure modulated exclusively in operation by the inherent flexibility and resilience of said saws, and driving means for imparting cutting movement to said edges, to cut the laminae from the stem.

5. In a tobacco stemming machine, a pair of nat iiexible band saws having their faces opposed and in position to engage a stem between them, said saws having arcuate cutting edges in continuance of said faces for cutting the laminae from a stem passing between said members, said adjacent arcuate cutting edges operating exclusively upon the portions of the laminae contiguous to the stem on each side, thereby to avoid cutting into the stem.

WILHELM B. BRONANDER. 

